Duelling in the C18th'd be smallsword (assuming you're not somewhere Mediterranean for which you'd need knives) for which this book'd be ideal and was cretaed with fellows such as you in mind with additional essays on how to practice etc-http://www.wyvernmedia.co.uk/shop#!/The ... ry=2613218

I hear the translator is a lovely fellow and easily contacted for lessons and further instruction

For something more diverse I'd go with Walker's "Defensive Exercises"- a book intended to give a Regency Buck or chap-about-town the basics of every martial skill of the era for personal defence and recreational fun.